During the course of a zombie outbreak, the corpse count will undoubtedly be incredibly high. Given the dual problem of a rising body count and the body count that rises, corpse disposal becomes an important (but macabre) necessity.
There are multiple ways that this can be done, as well as many consequences for neglecting or half-assing it. Regardless of the method, the dehumanizing process wreaks havoc on the morale of even the most hardened of hearts. Even if they were zombies before being killed (again), the stillness of death brings with it the glimpse of who they ultimately were: the deceased victims of the terrible outbreak.